Plasma ignition for direct injected internal combustion engines

ABSTRACT

An apparatus and method for the creation, placement and control of an area of electrical ionization within an internal combustion engine combustion chamber. This area of electrical ionization is positioned so that all of the fuel being injected into the combustion chamber must pass next to or through the area of electrical ionization to ensure that combustion has been initiated for all of the fuel as it is injected. This area of electrical ionization can be kept on as long as it is necessary to insure that the all of the fuel that is injected into the combustion chamber can be completely combusted. An engine equipped with this electrical ionization device has its fuel economy enhanced by timely, controlled, and complete combustion of all of the fuel injected into its combustion chamber. Furthermore, the pollutant emissions of both oxides of nitrogen and unburned hydrocarbons are reduced dramatically. Further, cold starting capability of this engine is greatly enhanced by a major reduction in the time necessary for the engine to warm up and a major reduction of pollutants created by the engine during the warm-up period. Additionally, this method of combustion also allows the engine to operate at a higher speed (rpm) allowing an increase in peak power output.

[0001] This new application is a continuation application of U.S.application Ser. No. 09/954,195 filed on Sep. 18, 2001, currentlypending, which is a continuation application of U.S. patent applicationSer. No. 09/501,788 filed on Feb. 11, 2000, now U.S. Pat. No. 6,289,868issued on Sep. 18, 2001.

BACKGROUND OF THE INVENTION

[0002] 1. Field of the Invention

[0003] The present invention relates to a method and apparatus forassuring combustion of fuel injected in a combustion chamber of aninternal combustion engine.

[0004] 2. Description of the Related Art

[0005] Diesel engines of both the 2-cycle and 4-cycle types haveenormous acceptance throughout the world and they are also the types ofengines that would benefit the most from application of the presentinvention. When engine longevity and fuel economy are more importantthan the power-to-weight ratio or the ability to operate through a widerange of engine speeds, diesel fueled engines are ideal.

[0006] Both Sir Harry R. Ricardo in his book The High Speed InternalCombustion Engine and Charles Fayette Taylor in his two volume set TheInternal Combustion Engine in Theory and Practice states that once thepiston in a diesel engine goes more than about one third of the way downon its power stroke, the flame in the combustion chamber goes out.Although diesel engines have much better fuel economy than that ofgasoline engines of the same power output, the diesel engines fueleconomy is still constrained by the time needed for complete combustion.

[0007] In an engine that is dependent upon the heat of compression toinitiate and maintain combustion, the relatively slow process of fuelinjection, mixing of the fuel with the air, and the combustion itselfmust take place before the flame goes out as the piston travels past thefirst third of its power stroke.

[0008] The primary cause of diesel engine pollution is its dependenceupon the heat of compression inside the combustion chamber forinitiation and maintenance of the combustion process. Regardless ofengine rpm, the actual time (not degrees of crank rotation) that ittakes for the fuel and air to mix and burn is relatively long becausediesel fuel is notoriously hard to ignite and keep burning.

[0009] This difficulty of ignition can be demonstrated from putting outa match by dipping it in a cup of diesel fuel. This can also bedemonstrated by placing a conventional spark plug in the fuel spraypattern of a fuel injector. When diesel fuel is injected into a sparkplug's gap, the spark is extinguished there and the spark then takesplace outside of the combustion chamber by taking a path outside of thespark plug ceramic insulator from its high voltage terminal to itsthreaded base. The difficulty of igniting diesel fuel with a spark plugis demonstrated further by the absence of spark assisted diesel enginesfrom the market.

[0010] For the heat of compression in a diesel engine to be sufficientfor the initiation of the combustion process, the compression ratio mustbe relatively high. In some engines this compression ratio is as high as18 to 1. This results in a very high combustion chamber pressure evenbefore the fuel is injected into the combustion chamber. Sincecombustion starts at an already high pressure, the combustion chambertemperature and pressure quickly increase to the point where the oxygenand nitrogen that are naturally present in air combine to create oxidesof nitrogen (also referred to as NOx). Pollution from these oxides ofnitrogen is the primary cause of acid rain, photo-chemical smog and ahost of other very serious ecological and health problems.

[0011] The actual time needed for complete combustion to take place in adiesel engine is the primary cause of the other main type of pollutantemissions from diesel engine operation.

[0012] Any fuel that is not combusted or partially combusted as thepiston goes down past a third of the way down its power stroke nevergets burned. This problem becomes worse if the engine is operating atfull speed (as measured in revolutions per minute) and/or at full power.Any partially or not combusted fuel left in the combustion chamber whenthe piston travels past the first third of the power stroke then exitsthrough the exhaust port as unburned hydrocarbons, partially combustedhydrocarbons, and particulate matter, all of which together are morecommonly referred to as smoke. Making this pollution even worse is thefact that the NOx created reacts with the water naturally present inengine exhaust to make nitric acid. This nitric acid then in turn reactswith the smoke to create a carcinogenic stew of truly unhealthy anddangerous chemicals. These chemicals are so harmful that under presentFederal law, they could not be accepted by a landfill in the form ofsolid or liquid waste.

[0013] Until very recently, the only “pollution control device” that wasinstalled on diesel engines in the United States was an engine speedgovernor. The function of this governor was to make sure that enoughtime was allowed during the power stroke so that sufficient combustiontook place prior to the piston traveling past the first third of itspower stroke in order to prevent the creation of visible smoke by theengine. All too often truck operators disable this governor so that theycould squeeze a little extra power out of their engine while going uphill or passing other vehicles. Their ecological irresponsibility isevident from the enormous black clouds belching out of their exhauststacks and left in their wake.

[0014] The Environmental Protection Agency (henceforth referred to asthe EPA) has allowed until recently for diesel engines to be“grand-fathered” out of earlier pollution control regulations. This wasdone for three reasons:

[0015] 1. Diesel engines get much better fuel economy than gasolineengines of the same power output;

[0016] 2. The currently accepted theory of operation for diesel enginesdid not allow for major changes in design that could be applied in acost-effective manner; and

[0017] 3. There was not any readily available alternative type of enginedesign that could perform the jobs currently done by diesel engines.

[0018] Over the last three decades this has resulted in a slower pace ofdesign advancement for diesel engines, especially for pollutionreduction, when compared to design advancements made on gasolineengines. As a result diesel engine design has improved onlyincrementally over the last thirty years without major reductions inpollutant emission levels.

[0019] During the same period of time, an outstanding job of cleaning upgasoline engines and other industrial sources of air pollution tookplace. However, air pollution created by diesel engines has remainedabout the same for a given amount of power produced. This caused therelative percentage of air pollution produced by diesel engines tobecome the primary cause of air pollution in the US.

[0020] In response to this, the EPA started looking into ways to reducediesel engine pollutant emissions. They mentioned several possible meansto achieve this in a fact sheet issued in October 1995 (EPA420-F-95-009a) that included “after treatment” such as catalyticconverters, fuel delivery control systems, air intake strategies, andchanging diesel fuel formulations. This was followed in August 1998 by aRegulatory Announcement-New Standards for Nonroad Diesel Engines (EPA420-F-98-034) that phase in reduction of diesel engine emissions by 66%over a ten year period.

[0021] Very specific procedures to verify regulatory compliance of newengine designs were put forward by the EPA in March 1999 in theirdocument titled Certification Guidance for Engines Regulated Under: 40CFR Part 86 and 40 CFR Part 89. Going through these procedures to get anengine certified are an enormous task in themselves and actually meetingthese standards for EPA certification is a major accomplishment.

[0022] Over the years there has accumulated a large body of prior artthat discloses a variety of approaches for providing assistance to thediesel engine combustion process. A variety of reasons have motivatedthese efforts, primarily to improve fuel economy, enhance engine power,and reduce pollutant emissions.

[0023] Rao et al. (U.S. Pat. No. 5,307,772) discloses a means to assistthe diesel combustion process through the use of a catalyst. Thiscatalyst is plated onto a structure that is placed between thepre-combustion chamber and the main combustion chamber in the cylinderhead on a diesel engine. This catalyst-coated structure is positioned sothat combusting gasses under high pressure and at high velocities mustpass through it during each power stroke.

[0024] Fukano et al. (U.S. Pat. No. 5,224,449) and Ariga (U.S. Pat. Nos.4,913,111 and 4,686,941) disclose improvements to spark-assisted dieselengines that consist of inducing turbulence to the combusting fuel-airmixture. In all three patents secondary combustion chambers are used tocreate the desired turbulence to enhance the mixing of the fuel and air.In addition to aiding the mixing process, the turbulence also exposesthe spark on the tip of the spark plug to more of the fuel-air mixture.Although these systems may enhance combustion to some extent, the sparkplug itself is only exposed to one specific point of the fuel-airmixture at any given time.

[0025] McCowen et al. (U.S. Pat. No. 5,855,192) disclosesfuel-preheating elements, combustion chamber heating elements, and aheat retention element within the combustion chamber. The application ofheat to the fuel and to the combustion chamber may assist the combustionprocess, especially during cold starting, as shown by the use of glowplugs and fuel pre-heaters in diesel engines currently in production;but there is a drawback to the introduction of additional heat into thecombustion process in that it will result in greater creation of oxidesof nitrogen. Another problem with this approach is the relativeinefficiency of electrical resistance heating elements in terms of thepower that they require, and their relatively short life in terms oftotal hours of operation after which they need to be replaced.

[0026] Chan (U.S. Pat. No. 5,852,999) discloses another example ofcreating and maintaining a spark that can be used in a spark assisteddiesel engine. A two-point electrode arrangement is disclosed that isprovided with a high frequency electrical current to create anelectrical arc inside the combustion chamber. The main point in thedisclosure by Chan is the concept of having the high frequency arcinitiated while the piston in the combustion chamber is at bottom deadcenter of the compression stroke. This is done for the purpose ofreducing the voltage needed to initiate the arc.

[0027] Casey (U.S. Pat. No. 4,111,178) and Kindermann et al. (U.S. Pat.No. 4,096,841) both disclose reciprocating 4-cycle direct injected sparkignited gasoline-fueled engines. The system disclosed consists of a fuelinjector and a spark plug placed in a pre-combustion chamber with thespark timing controlled by a signal that originates in the fuelinjector.

[0028] None of these references disclose an apparatus that will allowfor the initiation of combustion for all of the fuel as it is injectedinto the combustion chamber followed by the maintenance of thecombustion process to its completion in the manner described herein.

SUMMARY OF THE INVENTION

[0029] It is accordingly an object of the invention to provide anapparatus and method for assuring the combustion of the fuel injectedinto the combustion chamber of direct injected internal combustionengines such as diesel and gasoline engines of the reciprocating “pistonin cylinder” type as well as gas turbines.

[0030] It is a further object of the invention to eliminate thedependence of diesel engines upon the heat of compression to initiateand maintain its combustion process.

[0031] It is a further object of the invention to improve the fueleconomy of direct injected engines.

[0032] According to these objects of the present invention, an area ofionizing electrical energy (for purposes of illustration it is referredto as a “Ring-of-Fire”) is created inside the combustion chamberdirectly in front of or adjacent to the fuel injector nozzle which thefuel must pass through or next to as it enters the combustion chamber.Additionally this Ring-of-Fire will be kept on as long as needed so thatthe present invention will provide a means for the immediate,controlled, and complete combustion of all of the fuel injected into anengine combustion chamber.

[0033] When used in a reciprocating internal combustion engine, theengine can completely combust its fuel earlier in the power stroke,resulting in an improvement of fuel economy. There are at least fourreasons for this improvement in fuel economy (the first two arediscussed in greater detail later):

[0034] 1. Assuring the complete combustion of the fuel inside thecombustion chamber, when and where it does the work rather than wastingit by allowing un-combusted and partially combusted fuel to escape outthrough the exhaust port;

[0035] 2. Avoiding the endothermic chemical reaction that creates oxidesof nitrogen (NOx);

[0036] 3. Reducing pumping losses when an engine equipped with thepresent invention is operating at less than full power. This isespecially important for automotive diesels since they spend much moreof their operating time cruising at partial power or idling than they doat full power. The only time that an automotive diesel engine is run atfull power is when the vehicle is either going up hill or beingaccelerated. Since the present invention assures combustion regardlessof pressure, pumping losses can be reduced by throttling the airentering the intake manifold;

[0037] 4. Improving the effective ratio of expansion during the enginepower stroke. An engine equipped with the present invention has the fuelburn completed earlier in its power stroke, thus improving the effectiveratio of expansion which improves thermal efficiency.

[0038] It is also an object of the present invention to improve thepower output available from direct injected internal combustion enginessuch as diesel engines. Accordingly, engines so equipped can be run atfull power while still completely combusting all of the injected fuelmuch more rapidly within the combustion chamber allowing for higherengine speed without creating unacceptable exhaust emissions. Thishigher peak engine speed, as measured in revolutions per minute (rpm),translates directly into a higher peak horsepower.

[0039] An additional object of the present invention is to reduce thepollutant emissions created by the operation of direct injected internalcombustion engines. Although most of the direct injected engines in theworld today are diesels, the present invention will provide these samebenefits to gasoline and alternative fueled engines as well.

[0040] Hydrocarbon pollutant emissions are greatly reduced by thecomplete and timely combustion of the fuel and air within the engine'scombustion chamber. By keeping the Ring-of-Fire on as long as needed,complete combustion inside the combustion chamber is assured which willimprove fuel economy in addition to reducing hydrocarbon emissions.

[0041] Due to this ability of the present invention to assure completecombustion of all of the fuel inside the combustion chamber, engines soequipped will produce much fewer hydrocarbon emissions during a coldstart before the engine has run long enough to warm up. This will avoidthe creation of what the EPA refers to as the “hydrocarbon bubble”during warm-up of the engine, which is an area of pollution control thatthey are especially interested in.

[0042] The creation of oxides of nitrogen (NOx) will also be reducedsignificantly, especially in diesel engines, by the use of the presentinvention. Engines so equipped are freed from their dependence upon theheat of compression to initiate and maintain the combustion process. Asa result of this, diesel engines equipped with the present inventionwill dramatically reduce the creation of NOx in three ways:

[0043] 1. The mechanically defined compression ratio can be reducedwithout unacceptably degrading performance;

[0044] 2. The timing of the initiation of fuel injection can be retardedin terms of degrees of crankshaft rotation without unacceptablydegrading performance;

[0045] 3. The rate of injection can be controlled by a closed-loopfeedback system such as an engine management computer responding inreal-time to combustion chamber pressure and temperature. Since thepresent invention assures combustion of the fuel upon injection, itbecomes possible to regulate the rate of injection so that thetemperature and pressure inside the combustion chamber will be keptbelow the threshold above which NOx is formed.

[0046] How this is achieved can be visualized by a graph of therelationship between piston position during its power stroke and thepressure inside the combustion chamber of an un-modified diesel engineversus the graph made by the same engine after it has been equipped withthe present invention. The curve produced by the un-modified enginewould show the pressure rise inside as the piston approached top deadcenter followed by a sharp rise occurring as the fuel is being injectedinto the combustion chamber. Shortly after all of the fuel has beeninjected, the pressure will reach its peak after which it will startdropping off. It is during this period of high pressure that oxides ofnitrogen (NOx) are formed. An even more precipitous drop in combustionchamber pressure will follow this once the flame goes out as the pistontravels past the first third of its travel down during the power stroke.Any fuel that has not been fully combusted by this time will go out theexhaust as smoke.

[0047] In contrast, the same engine equipped with the present inventionwill have all of the fuel injected into the combustion chamber ignitedas it is being injected regardless of the injection timing and rate orthe combustion chamber temperature and pressure. Because of this, duringthe power stroke, the pressure and temperature inside the combustionchamber can be controlled so that it is maintained at a level that isjust below the threshold at which NOx is formed for as long as necessaryto deliver the power needed. This will create a flat pressure “curve”for much of the power stroke of an engine equipped with an enginemanagement computer that is controlling the timing and rate of fuelinjection in conjunction with the present invention assuring the timelyand complete combustion of the fuel.

[0048] When the two piston position to pressure curves are compared, theengine equipped with the present invention will have a lower peakpressure while maintaining an equal or greater area under the curve.This area under the pressure curve, not the peak pressure, relatesdirectly to the power produced. Any engine tuning arrangement is acompromise between power, fuel economy, and pollutant emissions controlwith the present invention offering the engine designer unprecedentedflexibility for achieving improvements in all areas of performance.

[0049] Ruman et al. (U.S. Pat. No. 5,924,404) discloses an enginemanagement system for use in 2-cycle direct injected spark ignitedgasoline fueled engines. An arrangement of a fuel injector and aconventional spark plug inside the combustion chamber which enables a2-cycle engine to reduce its emissions and improve its fuel economydramatically is disclosed. This control system could be adapted into thepresent invention by incorporating the appropriate software. It is alsopossible to adapt this control system for use in a 4-cycle reciprocatinginternal combustion engine.

[0050] Another object of the present invention is to enhance engine lifefor reciprocating internal combustion engines. Greater engine durabilityis the result of lower NOx emissions and lower peak pressures inside thecombustion chamber. When NOx is created during the combustion process,this NOx reacts with the water naturally created by the combustion tocreate nitric acid. This nitric acid accelerates engine wear, but ifnitric acid production during the combustion process is greatly reduced,engine durability is enhanced. Reducing the peak pressure within thecombustion chamber during the power stroke has the effect of loweringthe peak loads upon the engine bearings, further enhancing durability ofthe engine.

[0051] It is a further object of the present invention to make itpossible to retrofit existing reciprocating direct injected internalcombustion engines with the present invention at a minimum of expenseand time. The present invention can be installed on most diesel enginesin current use by removal of the cylinder head, installinginjector/igniter assemblies on that cylinder head, reinstalling themodified original cylinder head, and then installing the electronicsthat go with it. In most cases it will not be necessary to either removethe entire engine from where it has been installed or completely replacethe existing cylinder head. The importance of this retrofit applicationof the present invention to reciprocating 2-cycle and 4-cycle dieselengines cannot be overstated. The environmental and economic benefitsmade possible by the present invention are expanded dramatically as aresult of it being possible to retrofit existing engines. Reciprocatinginternal combustion engines retrofitted with the present inventionshould benefit from all of the advantages that are possible, with theexception of engine weight reduction.

[0052] It is also another object of present invention to make itpossible to design diesel fueled reciprocating internal combustionengines that weigh less for a given power output. Engine weight in newdiesel engines designed and produced with the present inventionincorporated into them can be designed to weigh much less for a givenpower output.

[0053] This is possible as a result of the lower peak combustion chamberpressures that occur in a reciprocating direct injected internalcombustion engine, such as a diesel engine, that has the presentinvention incorporated into it. Diesel engines currently beingmanufactured have to be designed to deal with very high peak pressuresinside of the combustion chamber that are necessary forheat-of-compression ignition to work. These very high peak pressures arealso responsible for the creation of NOx. Because lower peak pressuresinside the combustion chamber will occur in a diesel engine equippedwith the present invention, the engine block will be subjected to lowerpeak stresses making it possible to design the engine to weigh less fora given engine displacement and power output.

[0054] These objects of the present invention are accomplished bycreating an area of electrical ionization in front of or in closeproximity to the nozzles of the fuel injectors. When fuel is injectedinto the combustion chamber, it must pass through or next to this areaof electrical ionization. By having this take place, combustion isinitiated for all of the injected fuel as it enters the combustionchamber of any kind of internal combustion engine. This area ofelectrical ionization will be maintained as long as necessary to sustainthe combustion process. In the case of gas turbines, the Ring-of-Firewill be kept on continuously until the engine has warmed up to the pointthat the engine has reached an operating temperature at which combustionwill be maintained on its own. When used in the combustion chamber ofreciprocating type engines, the Ring-of-Fire will be kept going duringthe power stroke until the combustion process has been completed.

[0055] To do this, there are a number of electrodes placed so that theirtips define a polygon inside the combustion chamber that is in front ofthe nozzle of the fuel injector. When this polygon defined by theelectrode tips is energized electrically, it creates an area ofelectrical ionization also called the Ring-of-Fire. This Ring-of-Firewill ionize anything inside of it or in close proximity to it. For apintle type fuel injector, the spray pattern of the fuel being injectedinto the combustion chamber will for the most part, pass through thearea of electrical ionization defined by the polygon between theelectrode tips. For a hole type fuel injector, the spray pattern of thefuel being injected is in such close proximity to the Ring-of-Fire thatthe fuel entering the combustion chamber will be ignited by thisRing-of-Fire.

[0056] These electrodes are held in position by a ceramic sleeve thatsurrounds the barrel of the fuel injector and extends from thecombustion chamber through the cylinder head with the electrode wiresembedded inside it. The other end of the wires that are embedded in theceramic sleeve are connected to a set of spark plug type high voltagewires that are in turn connected to a high voltage electrical dischargesource. There are a wide variety of high voltage electrical dischargesources that could be used by having them integrated into the circuitrythat creates the Ring-of-Fire.

[0057] R. S. Warner developed a system that could be easily integratedinto the Ring-of-Fire high voltage electrical discharge circuitry. Thissystem was known as the Pulse-Tronic 1000 ignition unit and R. S. Warnerpresented a research paper about it to the Diesel & Gas Engine PowerDivision of the American Society of Mechanical Engineers during the ASMEDiesel & Gas Engine Power Conference and Exhibit held in Dallas, Tex. inApril, 1970.

[0058] An interesting feature of this system is its output of a train ofpulses used to initiate and maintain the combustion process inside thecombustion chamber. The Pulse-Tronic 1000 ignition unit was shown to becapable of successfully burning fuel air mixtures that were much leanerthan what could be ignited by conventional ignition systems. Lean fuelair mixtures are notoriously hard to ignite and keep burning and thefact that this unit could successfully do so indicates the generalsuperiority of this ignition system.

[0059] Although applied only to gasoline engines, this system may beused as the high voltage electrical discharge source for theRing-of-Fire circuit in the present invention. The Pulse-Tronic 1000ignition unit is self-contained and powered by mechanical energy fromthe motor via a fan belt or rotating shaft without the need of aconnection to a battery or other electrical power source.

[0060] Rich (U.S. Pat. No. 5,429,103) also discloses a means ofproducing a high voltage output with a waveform almost the same as thePulse-Tronic 1000 ignition unit developed by R. S. Warner. The Richpatent high performance ignition system is able to initiate and maintaincombustion of lean fuel air mixtures that are difficult to burn inengines that were equipped with it.

[0061] The high voltage electrical discharge circuitry that is used inthe preferred embodiment as realized in the operational prototypecreates a ball of plasma located directly in front of the nozzle of thefuel injector. This ball of plasma is remarkably effective at insuringcomplete combustion of all of the fuel injected through it.

[0062] None of the examples disclosed in the prior art propose a meansof creating an area of thorough electrical ionization in the combustionchamber and locating it so that all of the fuel being injected into thecombustion chamber must pass in close proximity or through the area ofelectrical ionization.

[0063] In the case of the present invention being applied to dieselengines, eliminating the dependency of the engine upon the heat ofcompression for the initiation and maintenance of the combustion processmakes it is possible to achieve real-time control of the completecombustion process. This gives the engine designer unprecedentedflexibility in tuning the engine to achieve what is needed for any givenapplication, be it fuel economy, power, or low pollutant emissions.

BRIEF DESCRIPTION OF THE DRAWINGS

[0064] The above and other objects and features of the present inventionwill be clearly understood from the following description with respectto the preferred embodiment thereof when considered in conjunction withthe accompanying drawings and diagrams, in which:

[0065]FIG. 1 is a cross sectional side view of the injector/igniterapparatus of the present invention installed in an engine cylinder head.

[0066]FIG. 2 is a cross sectional side view of the injector/igniterapparatus of the present invention installed in an engine cylinder headwith fuel being injected into the combustion chamber.

[0067]FIG. 3A is an enlarged side view of the lower end of theinjector/igniter apparatus that extends through the cylinder head.

[0068]FIG. 3B is an enlarged bottom view of the injector/igniterapparatus.

[0069]FIG. 3C is an enlarged side view of the injector/igniter apparatusrotated by 90 degrees from the view presented in FIG. 3A.

[0070]FIG. 3D is an enlarged perspective view of the injector/igniterapparatus.

[0071]FIG. 4A is an enlarged side view of the injector/igniter apparatuswith the Ring-of-Fire shown in operation.

[0072]FIG. 4B is an enlarged bottom view of the injector/igniterapparatus with the Ring-of-Fire shown in operation.

[0073]FIG. 4C is an enlarged side view of the injector/igniter apparatusrotated by 90 degrees from the view presented in FIG. 4A.

[0074]FIG. 4D is an enlarged perspective view of the injector/igniterapparatus with the Ring-of-Fire shown in operation.

[0075]FIG. 5A is an enlarged side view of the injector/igniter apparatuswith the Ring-of-Fire shown in operation and with fuel being injected bya pintle type of fuel injector.

[0076]FIG. 5B is an enlarged bottom view of the injector/igniterapparatus with the Ring-of-Fire shown in operation and with fuel beinginjected by a pintle type of fuel injector.

[0077]FIG. 5C is an enlarged side view of the injector/igniter apparatusrotated by 90 degrees from the view presented in FIG. 5A with theRing-of-Fire shown in operation and with fuel being injected by a pintletype of fuel injector.

[0078]FIG. 5D is an enlarged perspective view of the injector/igniterapparatus with the Ring-of-Fire shown in operation and with fuel beinginjected by a pintle type of fuel injector.

[0079]FIG. 6A is an enlarged side view of the injector/igniter apparatuswith the Ring-of-Fire shown in operation and with fuel being injected bya hole type of fuel injector.

[0080]FIG. 6B is an enlarged bottom view of the injector/igniterapparatus with the Ring-of-Fire shown in operation and with fuel beinginjected by a hole type of fuel injector.

[0081]FIG. 6C is an enlarged side view of the injector/igniter apparatusrotated by 90 degrees from the view presented in FIG. 6A with theRing-of-Fire shown in operation and with fuel being injected by a holetype of fuel injector.

[0082]FIG. 6D is an enlarged perspective view of the injector/igniterapparatus with the Ring-of-Fire shown in operation and with fuel beinginjected by a hole type of fuel injector.

[0083]FIG. 7A is a cross sectional side view of the injector/igniterapparatus of the present invention.

[0084]FIG. 7B is a top view of the injector/igniter apparatus of thepresent invention.

[0085]FIG. 7C is a bottom view of the injector/igniter apparatus of thepresent invention.

[0086]FIG. 8A is a cross sectional side view of the ceramic sleeveportion of the injector/igniter apparatus of the present invention.

[0087]FIG. 8B is a top view of the ceramic sleeve portion of theinjector/igniter apparatus of the present invention.

[0088]FIG. 8C is a bottom view drawing of the ceramic sleeve portion ofthe injector/igniter apparatus of the present invention.

[0089]FIG. 9 is a block diagram of the signal generation circuit portionof the present invention.

[0090]FIG. 10A is a timing signal diagram of the square-wave signalcreated by the square-wave generator in the signal generation circuit ofthe present invention.

[0091]FIG. 10B is a timing signal diagram of the six sequential signalscreated by the signal divider circuit in the signal generation circuitof the present invention.

[0092]FIG. 10C is a timing signal diagram of the six overlappedsequential signals created by the signal overlap circuit in the signalgeneration circuit of the present invention.

[0093]FIG. 11 is a schematic of one of the high voltage dischargecircuits of the present invention.

[0094]FIG. 12 is a diagram depicting all six high voltage dischargecircuits attached to the ceramic sleeve portion of the injector/igniterapparatus of the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0095] The invention will now be described in further detail inconnection with illustrative preferred embodiments for improvingcombustion in a direct injected internal combustion engine enabling theengine to achieve better fuel economy, reduced pollutant emissions, andmore power. Within the scope of the present invention, this system couldbe applied to gas turbines and to reciprocating internal combustionengines that are direct injected of either the 2-stroke or the 4-stroketype that have been designed for use with any type of combustible fuelincluding gasoline, diesel or jet fuel.

[0096] Referring to FIG. 1, the present invention is shown mounted in acylinder head 15 of a diesel engine. An engine block 11 has placedinside it a piston 13 and mounted on top of the engine block 11 is thecylinder head 15. A combustion chamber 17 is located inside the areasurrounded by the engine block 11, the piston 13, and the cylinder head15. Passing through the cylinder head 15 is a fuel injector 21 that hasits lower body surrounded by a ceramic sleeve 23. A fuel inlet 25attached to the upper portion of the fuel injector 21 has a fuelpassageway 19 that allows fuel to travel to a fuel injection nozzle 27.This fuel injection nozzle 27 protrudes into the inside of thecombustion chamber 17.

[0097] A plurality of embedded wires 29 travel from high voltageterminals 31 mounted on the ceramic sleeve 23 outside and above thecylinder head 15 through the length of the ceramic sleeve 23 includingsubstantially parallel to the lower portion of the fuel injector 21.These embedded wires 29 extend into the combustion chamber 17 aselectrodes 33. In this embodiment, there are six electrodes 33 arrayedaround and below the fuel injector nozzle 27 inside the combustionchamber 17. All six electrodes 33 are individually connected to highvoltage terminals 31 by their own embedded wire 29.

[0098] Referring to FIG. 2, pressurized fuel is shown entering the fuelinjector 21 through the fuel inlet 25, down fuel passageway 19, and thenout of the fuel injector nozzle 27 into the combustion chamber 17producing a fuel injection spray pattern 37. While this is happening, ahigh voltage discharge 35 occurs between all of the tips of the sixelectrodes 33 inside the combustion chamber 17, with the fuel injectionspray pattern 37 passing right next to, or through the high voltagedischarge 35. The power for the high voltage discharge 35 that occursbetween the six electrodes 33 is produced by a set of six high voltagedischarge circuits 51, 53, 55, 57, 59 and 61 (discussed in detail withreference to FIGS. 11 and 12).

[0099] A set of six spark plug type high voltage wires 39, 41, 43, 45,47 and 49 connects on one end to the set of six high voltage dischargecircuits 51, 53, 55, 57, 59 and 61. The other end of the set of sixspark plug type high voltage wires 39, 41, 43, 45, 47 and 49 have anexternally insulated connector 32 that secures and protects theconnection to the six high voltage terminals 31 mounted on the upperportion of the ceramic sleeve 23. This set of six high voltage dischargecircuits 51, 53, 55, 57, 59 and 61 is controlled by a signal generationcircuit 63 which has its position in the system discussed in connectionwith FIG. 12 and has its operation discussed in detail in connectionwith FIG. 9.

[0100]FIG. 3A is a side view of the lower portion of the ceramic sleeve23 that extends through the cylinder head 15 into the combustion chamber17. The fuel injection nozzle 27 at the end of the fuel injector 21 andelectrodes 33 are on the end of the ceramic sleeve 23 that faces intothe combustion chamber 17.

[0101]FIG. 3B shows the only part of the present invention that isactually exposed to the inside of the combustion chamber 17. The sixelectrodes 33 are arranged in a circular manner around the fuelinjection nozzle 27.

[0102]FIG. 3C shows the same piece of the present invention that isillustrated by FIG. 3A with the difference being that the image wasrotated by 90 degrees in order to clarify the shape and position of theelectrodes 33 on the end of the ceramic sleeve 23.

[0103] An oblique perspective of the lower portion of the ceramic sleeve23 further illustrates the placement relationship of the fuel injectornozzle 27 to the electrodes 33 in FIG. 3D.

[0104]FIGS. 4A, 4B and 4C provide the same set of views as FIGS. 3A, 3Band 3C the inclusion of the operation of the high voltage discharge 35.This gives further clarification of the placement of the high voltagedischarge 35 upon the electrodes 33 that are arrayed around the fuelinjector nozzle 27 on the end of the ceramic sleeve 23 that faces thecombustion chamber 17. This combustion chamber 17 could, within thescope of the present invention, be installed in any of a variety ofengine types to include gas turbines as well as reciprocating 2-cycleand 4-cycle diesel or gasoline direct injected internal combustionengines.

[0105]FIG. 4D also shows the same oblique perspective view of the lowerportion of the ceramic sleeve 23 as shown in FIG. 3D with the inclusionof the high voltage discharge 35 occurring between the six electrodes33. Other numbers of electrodes to create the Ring-of-Fire are possible.Also, the Ring-of-Fire is schematically illustrated in these figuressince it is difficult to illustrate completely.

[0106]FIGS. 5A, 5B, 5C and 5D show the lower portion of the ceramicsleeve 23 as shown in FIGS. 4A, 4B, 4C and 4D with the inclusion of fuelbeing injected by a fuel injector 21. The fuel injection spray pattern37 of a pintle type of the fuel injector nozzle 27 places a cone ofinjected fuel centered to the high voltage discharge 35 that occursbetween the electrodes 33 inside the combustion chamber 17. This insurescomplete combustion initiation of all of the fuel as it is injected.

[0107]FIGS. 6A, 6B, 6C and 6D show the lower portion of the ceramicsleeve 23 as shown in FIGS. 5A, 5B, 5C and 5D. The difference is thatthis time the fuel injector 21 has a fuel injector nozzle 27 of the holetype. The hole type fuel injector nozzle 27 produces a fuel injectionspray pattern 37 that has a set of lobes. Each lobe sprays directly nextto or through the high voltage discharge 35 thus insuring completecombustion initiation of all of the fuel as it is injected into thecombustion chamber 17.

[0108] Referring to FIG. 7A, the fuel injector 21 is installed insidethe ceramic sleeve 23. When fuel injection is taking place, a fuelinjector pump (not shown) sends pressurized fuel to the fuel inlet 25 ofthe fuel injector 21 in a manner known in the art. The pressurized fueltravels through fuel passageway 19 to the fuel injector nozzle 27 thatinjects the fuel into the combustion chamber 17. The ceramic sleeve 23surrounds the lower portion of the fuel injector 21.

[0109] The upper end of the ceramic sleeve 23 that is above the cylinderhead 15 has six high voltage terminals 31 that are connected to sixembedded wires 29 that extend from the top to the bottom of the ceramicsleeve 23. The lower ends of the six embedded wires 29 extend from thebottom of the ceramic sleeve 23 into the combustion chamber 17 as sixelectrodes 33. These six electrodes 33 are positioned such that theirtips are arranged so that they define a hexagon inside the combustionchamber 17 around and below the fuel injector nozzle 27. This placementis important to insure that the fuel injection spray pattern 37 from thefuel injector nozzle 27 must pass in close proximity to or through thehigh voltage discharge 35 that occurs between the tips of the electrodes33.

[0110]FIG. 7B shows a top view of the fuel injector 21 mounted throughthe ceramic sleeve 23 with the placement of the six high voltageterminals 31 clearly shown.

[0111]FIG. 7C is a view from the combustion chamber 17 looking up at theface of the ceramic sleeve 23 and at the tip of the fuel injector 21with the fuel injection nozzle 27 in the center of the six electrodes33.

[0112]FIGS. 8A, 8B and 8C are similar views as FIGS. 7A, 7B and 7Cwithout the fuel injector 21 being shown to further clarify thepositions of the high voltage terminals 31, the embedded wires 29 andthe electrodes 33.

[0113]FIG. 9 shows the signal generation circuit 63 in detail. Thesignal generation circuit 63 controls the high voltage generationcircuits 51, 52, 53, 55, 57, 59 and 61. The signals mentioned in thisdiscussion are shown in detail by FIGS. 10A, 10B and 10C.

[0114] The signal generation circuit 63 has its overall outputcontrolled by an engine timing signal source 65 that turns it on and offthrough an engine timing signal transmission line 67. The engine timingsignal source 65 controls the signal generation circuit 63 so that atthe appropriate time, at or before fuel injection is to take place, thehigh voltage discharge 35 is initiated. The engine timing signal source65 keeps the high voltage discharge 35 going for as long as necessary toensure complete combustion of all of the fuel and air mixture inside thecombustion chamber 17.

[0115] The signal generation circuit 63 has within it a square-wavegenerator circuit 69 that sends through a square-wave signaltransmission line 71, a square-wave signal 73 to a signal dividercircuit 75. The square-wave generator circuit 63 is based on a 555 timerintegrated circuit set up to operate as an astable multi-vibratorcircuit producing a square-wave signal between 0 and 5 volts at afrequency between 5 and 30 kilohertz.

[0116] The signal divider circuit 75 divides the square-wave signal 73into a set of six sequential signals 89, 91, 93, 95, 97 and 99, as shownin FIG. 10B, that are sent through a set of six sequential signaltransmission lines 77, 79, 81, 83, 85 and 87 to a signal overlap circuit101. The signal divider circuit 75 that divides the square-wave signal73 into a set of six sequential signals 89, 91, 93, 95, 97 and 99 isbased on the 4017 decade counter integrated circuit.

[0117] The signal overlap circuit 101 in turn generates a set of sixoverlapped sequential signals 115, 117, 119, 121, 123 and 125, as shownin FIG. 10C, and then sends these signals through a set of sixoverlapped sequential signal lines 103, 105, 107, 109, 111 and 113 to asignal line driver circuit 127. The signal overlap circuit 101 uses abank of twelve 1N4004 diodes to generate the set of six overlappedsequential signals 115, 117, 119, 121, 123 and 125 shown in FIG. 10C.

[0118] The signal line driver circuit 127 is activated only when theenable signal from the engine timing signal source 65, brought in by theengine timing signal transmission line 67 and it allows the set of sixoverlapped sequential signals 115, 117, 119, 121, 123 and 125 to gothrough the signal line driver circuit 127. The signal line drivercircuit 127 uses a 74HCT541 integrated circuit to act as a “gate” to theset of six overlapped sequential signals 115, 117, 119, 121, 123 and125.

[0119] It is within the scope of the present invention to have thisengine timing signal source 65 be as simple as a cam-shaft positionsensor, such as a Hall-effect sensor, or as complicated as a highlysophisticated engine management computer responding in real time to anumber of factors to include actual conditions inside of the combustionchamber 17 as they happen in real time as is known in the art. Whenenabled by the engine timing signal source 65, the signal line drivercircuit 127 then “cleans up” and strengthens the set of six overlappedsequential signals 115, 117, 119, 121, 123 and 125 without otherwisechanging them before they are sent out through a set of six controlsignal output lines 129, 131, 133, 135, 137 and 139 to each of the sixhigh voltage discharge circuits 51, 53, 55, 57, 59 and 61.

[0120]FIG. 11 is an electrical schematic for each high voltage dischargecircuit 51, 53, 55, 57, 59 and 61. Each of the six high voltagedischarge circuits 51, 53, 55, 57, 59 and 61 is connected to a 24 voltpower source 143 and to one of the six control signal output lines 129,131, 133, 135, 137 and 139. When a signal is received by its intendedhigh voltage discharge circuit 51, 53, 55, 57, 59 and 61 it turns on apower MOSFET 145 labeled Q-1. In one embodiment of the presentinvention, the power MOSFET (Metal Oxide Surface Effect Transistor) 145labeled Q-1 is a MTY55N20E made by Motorola and it is rated for 55 ampsat 200 volts.

[0121] When the power MOSFET 145 labeled Q-1 is turned on, a highvoltage transformer 147 labeled T-1 then has current flow from the 24volt power source 143 through a primary winding power lead 149. Thecurrent passes through a primary winding 151 of the high voltagetransformer 147 labeled T-1, through a primary winding ground lead 153,through the power MOSFET 145 labeled Q-1, through a resistor 155 labeledR-1 that is rated at 0.2 ohms and 10 watts, and then finally to a lowvoltage ground connection 157. This low voltage ground connection 157 isshared by all of the six high voltage discharge circuits 51, 53, 55, 57,59 and 61 and it is also used by all of the components of the signalgeneration circuit 63. There is a large value capacitor 159 labeled C-1which is rated at 1 microfarad and a small value capacitor 161 labeledC-2 which is rated at 0.01 microfarads. Both are attached in parallelacross the primary winding power lead 149 and the primary winding groundlead 153.

[0122] An electrically isolated secondary winding 163 of the highvoltage transformer 147 labeled T-1 has an electrically isolatedsecondary winding ground lead 165 connected to an electrically isolated“floating” high voltage ground 167 that is shared in the same positionof each circuit in all of the six high voltage discharge circuits 51,53, 55, 57, 59 and 61. The electrically isolated secondary winding 163of the high voltage transformer 147 labeled T-1 is connected to anelectrically isolated secondary winding high voltage output lead 169.The electrically isolated secondary winding high voltage output lead 169is in turn connected to the appropriate one of the set of six spark plugtype high voltage wires 39, 41, 43, 45, 47 and 49 which in turn areconnected to one of the set of six high voltage terminals 31 on theceramic sleeve 23.

[0123]FIG. 12 shows the overall combination of elements of theelectrical system according to the present invention. This includes a 5volt power source 171 used by all of the circuitry inside the signalgeneration circuit 63. Further a low voltage ground connection 157 isshown as being shared by all of the high voltage discharge circuits 51,53, 55, 57, 59 and 61 and with the signal generation circuit 63.

[0124] It should be appreciated that the other ways of creating andcontrolling the Ring-of-Fire high voltage discharge 35. Although anymeans of creating and controlling the Ring-of-Fire must place it so thatthe injected fuel spray pattern 37 go next to or through it as fuelenters the combustion chamber 17.

What is claimed is:
 1. A fuel combustion initiation device for anengine, comprising: at least three electrodes having electrode tips,said electrode tips being disposed in at least one of a combustionchamber and a pre-combustion chamber, said electrode tips defining anarea disposed in close proximity to a location where fuel is injected; asource of electrical energy that supplies said electrodes with power,said electrode tips being arranged so that electrical power is capableof selectively flowing from each electrode to the other electrodes toform a zone of ionization; and an engine management computer forproducing signals so that electrical power selectively flows from eachelectrode to the other electrodes in a predetermined pattern.
 2. A fuelcombustion initiation device as defined in claim 1, wherein saidelectrode tips form a polygon.
 3. A fuel combustion initiation device asdefined in claim 1, wherein said electrode tips include six electrodetips disposed around the location where fuel is injected.
 4. A fuelcombustion initiation device as defined in claim 1, further comprisingan insulated sleeve, said electrodes being at least partially disposedin said insulated sleeve.
 5. A fuel combustion initiation device asdefined in claim 4, further comprising a fuel injector disposed insidesaid insulated sleeve.
 6. A fuel combustion initiation device as definedin claim 1, wherein said electrode tips being arranged so that injectedfuel must pass through an area defined by said electrode tips.
 7. A fuelcombustion initiation device as defined in claim 1, further comprisingat least three high voltage electrical sources, each of said electricalsources supplying power to one of said electrodes.
 8. A fuel combustioninitiation device as defined in claim 1, further comprising a signalgeneration circuit that controls said source of electrical power tocreate the zone of electrical ionization.
 9. A fuel combustioninitiation device as defined in claim 1, further comprising an enginetiming signal source that controls the zone of electrical ionization byselectively energizing said electrodes to assist combustion.
 10. A fuelcombustion initiation device as defined in claim 1, further comprising aceramic sleeve that extends from said combustion chamber through acylinder head, said ceramic sleeve including wires embedded thereinforming said electrodes in the cylinder head, one end of said wiresbeing connected to a set of terminals for connected to said source ofelectrical power.
 11. A fuel combustion initiation device as defined inclaim 1, wherein the engine management computer controls an enginetiming signal for the source of electrical power.
 12. An ignitiondevice, comprising: at least three electrodes having electrode tips,said electrode tips being disposed in at least one of a combustionchamber and a pre-combustion chamber, said electrode tips being arrangedto define a polygonal area disposed in close proximity to a locationwhere fuel is injected; a source of electrical energy that supplies saidelectrodes with power, said electrode tips being arranged so that whenelectrical power is supplied directly to each electrode tip, an area ofelectrical ionization zone is formed; and a timing circuit for allowingthe source of electrical energy to selectively supply power to eachelectrode, wherein said timing circuit includes a signal circuit forallowing at least one electrode to be supplied with power that issubsequently discharged to at least two other electrodes.
 13. Anignition device as defined in claim 12, wherein said source ofelectrical energy further comprises at least two electrical powersources connected to at least two of said electrodes.
 14. An ignitiondevice as defined in claim 13, wherein said source of electrical energyfurther comprises at least one of said two electrical power sources isconnected to each of said electrodes.
 15. An ignition device as definedin claim 12, wherein said electrode tips include six electrode tipsdisposed around the location where fuel is injected.
 16. An ignitiondevice as defined in claim 12, further comprising an insulated sleeve,said electrodes being at least partially disposed in said insulatedsleeve.
 17. An ignition device as defined in claim 16, furthercomprising a fuel injector disposed inside said insulated sleeve.
 18. Anignition device as defined in claim 12, wherein said electrode tipsbeing arranged so that injected fuel must pass through as the polygonalarea defined by said electrode tips.
 19. An ignition device as definedin claim 12, further comprising at least three high voltage electricalsources, each of said electrical sources supplying power to one of saidelectrodes.
 20. An ignition device as defined in claim 12, furthercomprising a ceramic sleeve that extends from said at least one of saidcombustion chamber and said pre-combustion chamber through a cylinderhead, said ceramic sleeve including wires embedded therein forming saidelectrodes in said cylinder head, one end of said wires being connectedto a set of terminals connected to said source of electrical power.